The BBC's anti-disinformation team has been looking into misleading and false claims about coronavirus tests, a death in police custody and the origins of the pandemic.
Claim: Legislation will allow 'DNA harvesting' through Covid-19 tests
Social media posts shared more than 2,500 times have claimed incorrectly that recent legislation would allow the UK government to take DNA samples from people having a Covid-19 test.
This is a covert plan for the "harvesting and retention of DNA", they say.
But the legislation cited does not relate to samples taken for coronavirus testing.
It had nothing to do with testing, the Home Office told the BBC.
Its purpose was to extend the time DNA and fingerprint records could be kept under anti-terrorism laws, because staff with security clearance had had only limited access to their IT systems during the pandemic.
"Owing to the ongoing impact of coronavirus, the government has further extended the retention deadlines for biometrics data being retained by counter-terrorism policing for national security," an official added.
The claims emerged last week and spread across Facebook, Reddit and Twitter, with coronavirus sceptics, supporters of the anti-vaccination movement and anti-5G and QAnon conspiracy theories all questioning the legislation.
Claim: A man died in police custody after police clashed with protesters in London
At the weekend, thousands of people gathered at an anti-lockdown protest in London. According to the Metropolitan Police 32 arrests were made.
Someone who has gained a following on social media after falsely linking 5G networks to coronavirus posted on Facebook "the Met Police murdered an innocent man" on Saturday afternoon.
As the false story spread on social media and messenger apps, the Metropolitan Police issued a denial on their Twitter account.
1/4 - Police are aware of comments circulating on social media suggesting that a man taken unwell at a protest in #TrafalgarSquare yesterday had died. This is not the case.— MPS Events (@MetPoliceEvents) September 20, 2020
Officers attempted to speak with the man after a traffic cone was thrown towards them.
The man became unwell while being arrested, was taken to hospital and subsequently released into police custody, they said.
When we contacted the police on Monday, we were told that he remains in custody, having been arrested on suspicion of assault on police and possession of Class A drugs.
Claim: Covid-19 was created in a laboratory
Verdict: No evidence
The BBC science team has looked at claims that coronavirus was released from a lab and found no credible scientific evidence.
But now a Chinese virologist has claimed on British and American television the coronavirus is "not from nature" and was created in a Chinese lab.
Former University of Hong Kong research fellow Dr Li-Meng Yan, made these claims on ITV's Loose Women programme and then repeated them on Fox News.
Her research was posted on a website and has since been viewed more than 500,000 times.
Links to it have also been shared across multiple platforms, including Facebook, Instagram and Twitter.
It claims specific characteristics of the virus show it was artificially manipulated.
But the scientific basis for this has been dismissed by other scientists.
"While to a non-virologist this may seem legitimate," Columbia University virologist Dr Angela Rasmussen said, "the primary claims made in the paper are demonstrably untrue and easily debunked."
She said the characteristics of the virus that the paper claims are unusual arise naturally in other viruses, and there is no indication they have been engineered.
University of Southampton senior research fellow in global health Dr Michael Head pointed to a peer-reviewed study from March that found no evidence for the claim.
The new study had not been formally peer-reviewed, he said, and "does not obviously offer any data that overrides previous research".
Dr Andrew Preston, an expert in microbial pathogenesis, at the University of Bath, said the claims were "unsubstantiated."
Dr Li-Meng Yan has not responded to a BBC request for comment.
Claim: Masks can give you pleurisy
Verdict: No evidence
Posts claiming wearing a mask can cause pleurisy - an inflammation of the tissue around the lungs, sometimes caused by an infection - have been circulating on social media.
One post shared more than 1,200 times on Facebook shows a stained mask with the words: "Your child is going to get very sick very soon and it won't be with corona. It will be pleurisy. "
Another - shared more than 2,000 times on Facebook alone by users promoting an anti-vaccination agenda and opposing local lockdowns in the UK, Ireland, Romania and the US - describes testimony from a "friend" whose daughter is said to have become ill with pleurisy and blames wearing a mask.
But medical experts say there is no evidence masks can cause pleurisy.
The World Health Organization recommends:
- avoid touching a mask while wearing it
- dispose of single-use masks after use
- wash reusable masks frequently
Additional reporting by Alistair Coleman and Marianna Spring